Tape-supported slide-fastener and method of making same

ABSTRACT

In a slide fastener a helicoidally wound filament of synthetic resin having laterally extending coupling heads is interwoven with a stringer tape of primary warp and weft threads by a heavier secondary weft thread which passes over generally longitudinally extending root portions of the helicoid interconnecting successive loops thereof. The secondary weft threads, whose throw is substantially limited to the width of the helicoid, may consist of heat-shrinkable material and are anchored to the tape by being interwoven with secondary warp threads heavier than the primary warp threads. The interweaving involves use of a lower and an upper bobbin for the primary and secondary wefts, shedding of the secondary warp threads above and below a central level at which the helicoid is maintained, and shedding of the primary warp threads solely below the central level.

Unite States atet [191 Heidermann TAPE-SUPPORTED SLIDE-FASTENER AND METHOD OF MAKING SAME [75] Inventor: August Heidermann,

Wuppertal-Elberfeld, Germany [73] Assignees Opti-Hdding AG ,Glarus,

Switzerland [22] Filed: Sept. 14, 1971 [21] Appl. No.: 180,300

Related US. Application Data [63] Continuation-impart of Ser. No. 886,567, Dec. 19,

l969,abandoned.

[52] US. Cl 139/384 B [51] Int. Cl D03d 1/00 [58] Field of Search 139/384 B, 11, 20, 116;

[56] References Cited UNITED STATES PATENTS 3,487,511 1 H1970 Frohlich 139/384 B 3,605,206 9/1969 Frohlich 24/205.16 C

FOREIGN PATENTS OR APPLICATIONS 1,945,315 3/1971 Germany 24/205.l6

OTHER PUBLICATIONS Gr. Publication 1023422- l-l950- Kruse.

Primary ExaminerI-Ienry S. Jaudon Attorney, Agent, or Firm-Karl F. Ross; Herbert Dubno [5 7] ABSTRACT In a slide fastener a helicoidally wound filament of synthetic resin having laterally extending coupling heads is interwoven with a stringer tape of primary warp and weft threads by a heavier secondary weft thread which passes over generally longitudinally extending root portions of the helicoid inter-connecting successive loops thereof. The secondary weft threads, whose throw is substantially limited to the width of the helicoid, may consist of heat-shrinkable material and are anchored to the tape by being interwoven with secondary warp threads heavier than the primary warp threads.

The interweaving involves use of a lower and an upper bobbin for the primary and secondary wefts, shedding of the secondary warp threads above and below a central level at which the helicoid is maintained, and shedding of the primary warp threads solely below the central level.

9 Claims, 4 Drawing Figures PATENTEB W i 2 1974 I .xn'LU 1. [IF 3 August Heidermann INVENTOR.

w A ATTORNEY PAIENIED m 1 2 19m SHEEI 2 OF 3 m wt ugusf Heic/ermann INVENTOR.

{Karl ATTORNEY PAIENTED MR 1 2 i974 SHEET 3 OF 3 [Ill/III] Augus'f' Heidermann ZNVENTOR.

ATTORNEY TAPE-SUPPORTED SLIDE-FASTENER AND METHOD OF MAKING SAME The present application is a continuation-in-part of my copending application Ser. No. 886,567 filed Dec. 19, 1969, now abandoned.

My present invention relates to slide-fastener halves comprising coils of helicoidal configuration made usually of synthetic-resin monofilament, e.g., a polyamide or polyester, supported on a fabric tape by which the fastener coil is attached to the respective garment.

Various ways are known of attaching helicoidal coupling elements to their supporting stringer tapes.

According to one known procedure the helicoid is handled in a manner of a weft or warp thread and is interwoven with warp or weft threads of the tape. The interweaving threads then overlie the helicoid and are exposed to wear or damage either by the slider or otherwise, as a result of which the helicoid may become detached from the tape.

It is therefore an object of my present invention to provide an improved slide fastener of the abovedescribed type wherein the helicoid is attached to the tape at locations where the connecting threads are protected from wear and damage.

Another object is to provide a simple and efficient process form making a tape-supported slide-fastener half of this character.

The coupling element composed of synthetic monofilamentary resin, referred to hereinafter as a helicoid because of its shape, consists of a succession of turns comprising generally transverse loop portions interconnected by generally longitudinal links or root portions. In accordance with the present invention, these root portions constitute the principal or only zone of attachment tying the helicoid to the underlying fab- IlC.

Each upstanding loop portion, bearing edgewise on the tape, comprises a lateral leg having coupling heads formed on it. These coupling heads are adapted to interlock, by operation of the usual slider, with confronting coupling heads of the helicoid of a mating slidefastener half.

The loop portions of the fastener preferably lie in substantially parallel planes whose spacing is approximately equal to the caliber or gauge of the filament from which the helicoil is wound. The root portions generally extend at an acute angle with respect to the planes of the adjoining loops. Though integral with these loops, they may be flattened or reduced in thickness at their points of engagement by the threads that tie the helicoid to, or interweave it with, the tape.

In a preferred form of fastener the loops are oblong with elongate sections resting on the tape, the root portions branching off these sections near their midpoints so as to be in contact with the tape over their entire length. The root portions are therefore remote from the rising legs of the loops bearing the coupling formations.

In accordance with a more specific feature of my invention, the helicoid is attached to the tape by separate and preferably somewhat heavier threads passing over the root portions. These special threads, anchored to the tape by interweaving, shall be referred to as secondary weft threads and may advantageously be composed of a shrinkable material, e.g., a non-preshrunk synthetic polymer otherwise similar to that used for the helicoidal coil, in order to permit a particularly taut bond between helicoid and tape to be achieved by a shrinking step, such as the application of heat, after the helicoid is attached to its tape.

Secondary warp threads of similar character may also be provided which, in addition to the basic primary warp threads of the tape, are interwoven with the primary weft threads and provide anchoring points for the secondary weft threads looped about them. The secondary warp and weft threads may be limited to a relatively narrow longitudinal zone of the tape which may be narrower or only slightly wider than the area overlain by the helicoid.

The bond between helicoid and tape can be made particularly strong by employing secondary warp threads whose tensile strength exceeds that of the primary warp threads.

The interweaving of helicoid and tape may be carried out on a tape loom comprising a lower bobbin and an upper bobbin by maintaining the helicoid at a central level forming the boundary between a lower and an upper shed respectively traversed by these bobbins. The secondary weft thread is carried by one, preferably the upper, bobbin across the root portions of the helicoid to link up with the secondary warp threads which are partly halted at the central level and partly oscillated between an elevated position above and a depressed position below the central level. The primary weft thread is carried by the other, preferably the lower, bobbin which interweaves it with the primary warp threads, oscillated solely between the boundaries of one (preferably the lower) shed, and with the secondary warp threads periodically traversing that shed.

The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is a somewhat diagrammatic perspective view of a portion of a slide fastener embodying the invention;

FIG. 2 is a crosssectional view of the assembly shown in FIG. ll;

FIG. 3 is a plan view of the right-hand fastener half of FIG. 2; and I FIG. 4 is a diagrammatic illustration of an interweaving procedure for producing the fastener of FIGS. ll 3.

The slide fastener structure shown in FIGS. 1, 2 and 3 comprises a pair of stringer tapes 1 woven principally of primary weft threads 2 and primary warp threads 3.

Two slide-fastener halves 5 made of synthetic resinous monofilaments are wound in the shape of deformed helical coils.

Each turn of the helicoid 5 comprises an upstanding loop portion 15, a root portion 6 immediately overlying the tape 1 and a lateral leg having a coupling head 4 adapted to interlock with a pair of similar, longitudinally offset heads 4 on the other helicoid. The root portion 6 extends generally longitudinally between adjoining loop portions 15 integral therewith.

As seen more particularly in FIG. 3, the loop portions 15 lie in substantially parallel planes transverse to the longitudinal dimension of the fastener. The interconnecting root portions 6 therefore are angularly disposed with respect to the planes of the loop portions.

The root portions 6 may have flattened base surfaces and are anchored down on the tape by secondary weft threads 7 which pass over the root portions and are interwoven with the secondary warp threads 8a, 8b that are interspersed with the primary warp threads 3 of the tape 1.

The secondary weft and warp threads 7 and 8a, 812, whose thickness is somewhat exaggerated in the drawing but which are generally heavier than the threads 2, 3, may consist of a heat-shrinkable synthetic resin, a preferred shrinkage rate being of the order of 20 per cent.

FIG. 4 illustrates the basic steps of interweaving the aforedescribed warp and weft threads. The operation is preferably carried out on a tape loom having an upper bobbin 13 and a lower bobbin 1t) carried on respective shuttles 16, 17.

The helicoid 5 is shown to lie at a central level generally designated 11, advancing to the right at that level together with the warp. The primary weft thread 2 is carried by the lower bobbin and is interwoven with the primary warp threads 3 and also with the secondary warp threads 8a, 8b. For this purpose the primary warp threads 3 are oscillated in two oppositely moving groups, in timed relationship with the shuttle traverse, between a depressed position generally indicated at 9 and an elevated position at the central level ill. The secondary weft thread 7, which is carried by the upper bobbin 13, does not enter the lower shed formed by these two groups. As is apparent from FIG. 3, the shuttle 16 makes two passes between successive loops 15.

The weft 2 dispensed by the lower bobbin 10 may be a stranded cotton thread. The shrinkable thread 7 may consist of the same material as the secondary warp threads 80, 812 except that the latter may alreadybe preshrunk.

The coil 5 is fed to the level 11 at a location past the heddles (not shown) carrying the warp threads 3, 8a, 8b. With the secondary warp threads 8a, 8b confined to an area overlain by the coil 5, the warp threads 8a or 8b are cammed aside to clear the coil when oscillating past the level 11. The subsequent heat shrinkage of weft 7 helps lock these warp threads in their assigned position.

If desired, the secondary warp threads 8a, 8b could also be located completely outside the zone overlain by the coil 5 during the weaving process, this zone being kept free from primary warp threads 3 except in the region of its centerline; the shrinking weft 7 then draws the warp threads 8a, 8b under the coil 5 into the position'of FIG. 1.

Whereas each pair of warp threads 8a and 8b move into the elevated position 12 only during every other pass of the upper shuttle 16, this shuttle performing only two such passes for every loop 15, the lower shuttle 17 operates independently thereof at a substantially higher frequency to interweave the weft 2-not only with the warp 3 but also with the threads 8a, 8 b which oscillate in step with this shuttle between positions 9 and ill at those times when they do not rise above the latter level.

Position 9 may be regarded as the outer boundary of a first shed (i.e. the aforementioned lower shed) whereas position 12 constitutes the outer boundary of a second or upper shed; the two sheds have a common boundary at position or level 11. With one group of warp threads, 8a at the outer boundary of the upper shed, as illustrated in FIG. 4, the warp threads of the other group 812 oscillate between the two boundaries l l and 9 of the lower shed in the rhythm of the highfrequency motion of shuttle 17, and in step with the primary warp threads 3, to weave a portion of the tape 1 including as many passes of weft 2 as intervene between successive passes of weft 7. After the lowfrequency shuttle 16 has made its traverse through the upper shed, the roles of the two groups of secondary warp threads 80, 8b are reversed; thus, the weaving of the tape by means of shuttle 17 continues with warp threads 8a now oscillating between boundaries 9 and ll of the lower shed, in step with warp threads 3, whereas warp threads 8 b are withdrawn to the outer boundary 12 of the upper shed until after the, following traverse of shuttle to in the reverse direction. The result of this mode of operation is the pattern illustrated in FIGS. 1 3, with the root portions 6 of the monofilamentary coil 5 anchored by the weft 7 to the fabric ll.

If the stroke of the shuttle 16 is long enough, the weft 7 will include a small angle with the fell of the cloth at the end of that stroke and will readily drop into the space between the successive loop portions 15 whenever the previously elevated pair of warp threads 8a or 8b is lowered at least to the intermediate level 11. Thus, even if no traverse of shuttle l7 intervenes between successive passes of shuttle 16 placing the weft 7 between two loops 15, weft 7 will be securely lodged in its proper position within the fabric structure as the weft 3 is beaten up by the lay (not shown) in a subsequent weaving stage during which the shuttle 16 is inactive.

The term monofilamentary coil, as used above and in the appended claims, is not limited to resinous materials as mentioned above by way of example.

I claim:

1. A slide-fastener half comprising a stringer tape essentially consisting of interwoven warp threads and weft threads, and a monofilamentary coil extending parallel to said warp threads, said coil having upstanding, generally transverse loop portions bearing edgewise on said tape and further having generally longitudinally extending root portions interconnecting said loop portions, certain of said weft threads passing over said root portions and anchoring said coil to said tape, said loop portions being provided with coupling formations remote from said root portions;

said warp threads including first warp threads distributed over the entire tape and second warp threads limited to a region of reduced width in the vicinity of said coil, said certain of said weft threads being interwoven only with said second warp threads.

2. A slide-fastener half as defined in claim' 1 wherein said certain of said weft threads consist of a heatshrinkable material.

3. A slide-fastener half as defined in claim 1 wherein said certain of said weft threads and said second warp threads are heavier than the remaining threads of said tape.

4. A slide-fastener half as defined in claim ll wherein said certain of said weft threads, said second warp threads and said coil consist of synthetic polymeric material.

5. A slide-fastener half as defined in claim 1 wherein said loop portions lie in parallel transverse planes with said root portions extending at an acute angle thereto.

6. A slide-fastener half as defined in claim 5 wherein said loop portions have elongate tape-contacting sections, said root portions branching off said sections near the midpoints thereof and contacting said tape substantially over their entire length.

7. A method of making a slide-fastener half wherein a monofilamentary coil with generally transverse loop portions interconnected by generally longitudinally extending root portions is secured to a tape of fabric having warp threads parallel to said coil and weft threads perpendicular thereto, comprising the steps of:

a. weaving a tape by passing a first weft through a first shed formed by two oppositely moving groups of first warp threads;

b. advancing the monofilamentary coil parallel to said warp threads and in step therewith along a common boundary of said first shed and a second shed;

c. feeding two groups of second warp threads along with said first warp threads on opposite sides of said coil;

d. weaving one of said groups into said tape by oscil-.

lating the threads thereof in step with said first warp threads between said common boundary and an outer boundary of said first shed;

e. displacing the other of said groups to an outer boundary of said second shed while passing a second weft through said second shed and across the root portions of said coil to anchor same to said tape; and

f. repeating steps (d) and (e) with reversal of the roles of said groups of second warp threads.

8. A method as defined in claim 7 wherein the outer boundaries of said first and second sheds lie respectively below and above said common boundary.

9. A method as defined in claim 7, comprising the further step of heat-shrinking said second weft around said root portions after the weaving of said tape, thereby locking said second warp threads together in a region of the fabric overlain by said coil.

* =l l l= 

1. A slide-fastener half comprising a stringer tape essentially consisting of interwoven warp threads and weft threads, and a monofilamentary coil extending parallel to said warp threads, said coil having upstanding, generally transverse loop portions bearing edgewise on said tape and further having generally longitudinally extending root portions interconnecting said loop portions, certain of said weft threads passing over said root portions and anchoring said coil to said tape, said loop portions being provided with coupling formations remote from said root portions; said warp threads including first warp threads distributed over the entire tape and second warp threads limited to a region of reduced width in the vicinity of said coil, said certain of said weft threads being interwoven only with said second warp threads.
 2. A slide-fastener half as defined in claim 1 wherein said certain of said weft threads consist of a heat-shrinkable material.
 3. A slide-fastener half as defined in claim 1 wherein said certain of said weft threads and said second warp threads are heavier than the remaining threads of said tape.
 4. A slide-fastener half as defined in claim 1 wherein said certain of said weft threads, said second warp threads and said coil consist of synthetic polymeric material.
 5. A slide-fastener half as defined in claim 1 wherein said loop portions lie in parallel transverse planes with said root portions extending at an acute angle thereto.
 6. A slide-fastener half as defined in claim 5 wherein said loop portions have elongate tape-contacting sections, said root portions branching off said sections near the midpoints thereof and contacting said tape substantially over their entire length.
 7. A method of making a slide-fastener half wherein a monofilamentary coil with generally transverse loop portions interconnected by generally longitudinally extending root portions is secured to a tape of fabric having warp threads parallel to said coil and weft threads perpendicular thereto, comprising the steps of: a. weaving a tape by passing a first weft through a first shed formed by two oppositely moving groups of first warp threads; b. advancing the monofilamentary coil parallel to said warp threads and in step therewith along a common boundary of said first shed and a second shed; c. feeding two groups of second warp threads along with said first warp threads on opposite sides of said coil; d. weaving one of said groups into said tape by oscillating the threads thereof in step with said first warp threads between said common boundary and an outer boundary of said first shed; e. displacing the other of said groups to an outer boundary of said second shed while passing a Second weft through said second shed and across the root portions of said coil to anchor same to said tape; and f. repeating steps (d) and (e) with reversal of the roles of said groups of second warp threads.
 8. A method as defined in claim 7 wherein the outer boundaries of said first and second sheds lie respectively below and above said common boundary.
 9. A method as defined in claim 7, comprising the further step of heat-shrinking said second weft around said root portions after the weaving of said tape, thereby locking said second warp threads together in a region of the fabric overlain by said coil. 